Treatment of formed filaments



Patented Dec. 1, 1936 UNITED STATES 2,062,712 TREATMENT OF FORMED FILAMENTS August Hartmann, Berlin-Lichterfeldc, Germany,

assignor to The American Bemberg' Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application April 10, 1934, Serial No. 719,895. In Germany February 14.1933

7 Claims. (01. ii-,2)

' The present invention has to do with a new and novel method of moistening artificial silk yarn prior to its conversion into finished goods.

More specifically, the present invention relates to a novel method of controlling the moisture content of artificial silk yarn, so that a yarn is obtained having a moisture content which is considered most desirable and is required in the weaving and knitting trade.

10 One object of the present invention is. to provide a method of directly moistening the vartificial silk thread during its manufacture.

A further object of the present invention is to provide a method whereby the twisting process is repeated in order to obtain the desired moisture content of the yarn.

Further objects will become apparent from a study of the following specification and claims. In the manufacture of woven or knitted fabrics made partly or wholly from yarn of artificial origin it is necessary that the artificial threads have a certain moisture content. In the weavingtrade, for example, a moisture content varying from 14 to. 18% is considered most desirable. Since the artificial silk yarn ordinarily produced has only a moisture content of 11%, it is necessary to increase the moisture present in the yarn before itis ,converted into fabrics. Hitherto, this subsequent moistening has almost exclusively been carried out in the converters plants, and in such a manner that the artificial silk yarn in the form of skeins was first immersed in an aqueous bath containing soap or other preparations, then centrifuged,

and finally passed through a conditioning room in which air of approximately 30 C. circulated, whereby the moisture content of the yarn was slowly decreased to the desired degree. Another former method of subsequent moistening consisted in guiding the thread, drawn from a skein or a spool, over a freely rotating roller which is immersed in a soap bath, or other preparation, thus giving a moistening of the thread through the liquid adhering to the roller.

Still another method has been to moisten the yarn by placing it, when wound upon spools,

for a certain length of time in a receptacle in which an atmosphere of steam is maintained.

In accordance with a newer suggestion, the

last-mentioned method has been so changed that the moistening of the yarn wound upon shipping spools, for example, in the form of cones,

is carriedout by the manufacturer of the yarn.

The moistened spool is then packed in a wrapping which is impervious to steam, for example,

a wrapper of metal foil, and thus shipped to the consumer.

In all of these methods .it is necessary to first produce a completely finished and dry thread which is subsequently remoistened. It has been 5 found that these subsequent remoistening methods do not ofier a sufiicient guarantee of a really uniform conditioning. I The present invention concerns a method which overcomes these difliculties. According to 10 this process, the artificial thread is. provided with the desired moisture content directly during its manufacture. This is accomplished by extracting the moisture from the thread immediately after its customary wet-treatment only 15 to the required limit of below 20%, which has been found, to be most suitable for the subsequent handling of the yarn.

The artificial silk, -for example artificial viscose yarn or cuprammonium yarn, either in the form 20 of skeins or spinning cakes, is subjected in a wellknown manner to the various chemical wet-treatments in order to be deacidified, decoppered, bleached, desulphurized and the like. The aftertreatment may also be carried out in two opera- 25 tions by the insertion of an intermediate drying which sometimes is desired.

In accordance with the present invention, the yarn package (skein, cake and the like) obtained after finishing these wet-treatments is freed of 3 the main portion of adhering wash water by means of centrifuging. Thus a decrease of the moisture content from approximately 400% to approximately200-% is obtained. The further reduction of the moisture content from the 35 yarn package is accomplished through twisting of the thread in the wet state. This operation results in an extraction of moisture in two ways. First, a comparatively large portion of moisture is extracted from the yarn while on the twisting 40 spool due to the efiect of thecentrifugal force, because the twisting spools rotate at a very high speed. Second, a further removal of moisture takes place during the passage of the thread from the twisting. spool to the take-up speed because 45 of the ballooning of the thread, caused by the fact that the twisting spool rotates at a considerably higher speed than the take-up spool. The latter step is of especial importance because the extraction of moisture exercised upon the single 550 thread is carried out under conditions which remain completely constant during the entire operation, since a change of speed of the twisting spool or of the take-up spool, does not take place. Minor irregularities which might have occurred 55 during the first step of the extraction of moisture, are removed, and thus a product possessing In many cases where the room temperature is less than 25 C. it might happen that one twisting will be insufficient to reduce the moisture content of the yarn to the desired degree, and a repetition of the twisting process will therefore be unnecessary. In accordance with the present invention, this method of operation is carried out as follows. It is known to spin cuprammonium yarn in a spinning funnel, to stretch the thread after leaving the funnel by means of friction thread guides or between stretching rollers rotating at different peripheral speeds, and to wind the thread after the usual acidification upon reels. These skeins are then removed from the reels and subjected to a washing process in order to remove the copper and the acids, and finally they are soaped. The soaped skeins are wrapped in cheese cloth and centrifuged, therebins are now placed in a double-deck twisting by reducing the moisture content to approximately 160%. They are then placed upon a reel which preferably is covered with an oilcloth support. On a winding machine, the thread is wound onto bottle bobbins. The wet bottle bobmachine and wound onto disk spools; The takeup of the disk spools, for example, may be meters per minute and the speed of the twisting spool 4000 revolutions per minute. Owing to the centrifugal force exercised upon the twisting spool, and the ballooning of the thread, the moisture content of the yarn is reduced to approximately 40%, based upon a room temperature of 20 C. and an atmospheric moisture of approximately 80%, which conditions ordinarily prevail in winding or twisting rooms. The disk spool thus obtained is placed in another twisting machine operating at a speed of 5000 revolutions per minute and a take-up of 50 meters per minute. Due to the higher speed and higher takeup prevailing during the second twisting operation, the thread obtains an additional twist, and the moisture content is reduced, for example, to 17%. As a take-up spool one may either use a disk spool, or a cone, or the like. After this second twisting process the yarn possessing the desired and absolutely uniform moisture content is in an available condition, which is suitable for the immediate use in weaving or knitting plants. In case the yarn is shipped to customers, the completely conditioned yarn package is packed in a well-known manner in a wrapper which is impervious to steam.

Having now set forth the new invention as required by the patent statutes, what is desired to be claimed is: I

1. In the manufacture of yarn of artificial origin, the steps of wet-treating extruded yarn, centrifuging while wet, and twisting the undried yarn until a moisture content of from 17 to 20% results.

2. In the treatment of wet-treated undried yarn, the steps of twisting the yarn while wet,- thus reducing the moisture content of the yarn, and then retwisting the yarn to further reduce its moisture content. I

3, In the treatment of wet-treated undried yarn, the steps of twisting the yarn while wet, thus reducing the moisture content of the yarn to approximately 40%, and then retwisting the yarn to further reduce its moisture content so that the final product contains from 17 to 20% of moisture.

4. In the treatment of wet-treated undried -yarn, the steps of centrifuging the yarn in the form of skeins, cakes or the like, winding it upon bottle bobbins, twisting and retwisting it at a room temperature of from 20 to 25 C. until a moisture content of from 17 to 20% results.

5. In the production of yarn which is moisture conditioned for use in the textile industry, the steps of extruding and wet-treating the yarn, then, without prior drying, twisting the yarn so that the moisture content thereof is reduced to between 17 and 20%, and finally marketing the yarn in a moisture proof wrapping in order that the moisture content of the yarn will remain unchanged.

6. In the manufacture of conditioned yarn by the cuprammonium process, the steps of extruding the yarn into a coagulating or hardening medium, stretching the yarn thus formed, collecting it, wet-treating it to decop, deacidify, etc., and then twisting and retwisting the yarn until the moisture content is reduced to 20% or less without the aid of any dryingsteps.

7. In the production of yarn of cellulosic origin which has not been subjected to a drying operation, the steps of extruding a cellulosic solution 

